Stars near Sagittarius A* and their orbits

Purpose

Sagittarius A* (SgrA*) is situated at the center of our galaxy and scientists have good evidence that this is in fact a black hole with a mass of four million suns. Most evidence comes from the observation of the movements of stars in the very neighbourhood of SgrA*.
This applet lets you observe the orbits and movements of some of these stars in a 3D presentation.

Usage

• Select one (click) or more (ctrl-click) of the three files StarOrbitsGalCenter...
  To compare the distances, you may also select Solar System for comparison
  
• The file Xtended view SolSyst in MW shows a schematic view of the Milky Way with the Solar System approximately correctly placed. If you add one of the previous files you can zoom in to more than 1000 and see the central stars again. If you double-click the dot representing the solar system, this point will be centered, and by zooming to more than 100 000 you will see the planets of the Solar System.
  The file lets you get a feeling of sizes relative to the Milky Way
• To get the 3D impression, you should drag the mouse on the applet.
• With any of the files, the stars and planets may be animated, please use the appropriate command and a sufficiently long time unit (month...)
• If you get lost (no objects on the screen), reset zoom to 1 and click Reset center button.
• The commands are a subset of those of the Large Structures Applet and on that page you will find further explanations.
  

Files

My applets have benefited from data compilations made by others. I have adapted files as they appear on several sites, especially

• Gillessen et al. page 24 in http://arxiv.org/abs/0810.4674

You should use the button "Data" down left in the applet to see more details concerning the sources of each individual file.